Clean room ceilings, which term includes ceiling sections, and enclosed area walls and floors with a similar purpose, typically comprise a plurality of high efficiency filter units, e.g. HEPA and ULPA and similar filter units, arranged in rows and columns and supported by a suspension attached to an adjacent support surface, most commonly the true ceiling of room in which the clean room is located.
In an installation of a great number of filter units tolerances in the dimensions of the units may stack, resulting in misalignment of the filters with their suspension components, making completion of the installation difficult and problematical.